new dryer and still hard to build pressure

Ok guys put a new a9 dryer cause I thought the purge vavle was bad on the oil unit but got the same problem with the new dryer...it just run to long before building pressure then once it builds and you use the brakes it doesn't come back on til its at 60 sometime the buzzer comes on..what should I be looking for on this..

 

right on the side of the compressor under the gov. where the gov. unit bolts to the compressor ( bolts to the compressor and 2 bolts up top ) I guess the is the fresh air unit has a holes coming of the side of the motor..anyway I replaced the gasket there and it has a leak...sounds like the purge valve a little but it is coming from right where the 2 goes together ...how can I stop this leak????I replaced the gasket and its still blowing from there....but it doesn't do it all the time...is this a part of the gov. unit??????

 

the dryer is a new unit just put on yesterday .......cause of this same issue..

 

this is the part that is leaking the gov. sits on top of it and the 2 bolts at the bottom is the 1 with the gasket..but I have replaced this gasket 2 times already and still has the leak..what do I need to be looking for to stop this leak...also the pressure will go to about 100 the blow off use to go to 120 and drop to about 80 now it drops to 60 and the buzzer will come on then it will start to build..

 

will try it again heavyd...yeah its a older unit my truck is a 1997 fld freighliner...